"The One Where Chandler Can't Remember Which Sister". Bobby Bobby (Marc Rose): Dina Tribbiani's boyfriend and her unborn child's father. Dr. Long Dr. Long (Amanda Carlin): Rachel's obstetrician, who appears in five episodes of season 8. She delivers the baby in "The One Where Rachel Has a Baby" after Rachel's extremely long labor. Eric Eric (Sean Penn): Ursula Buffay's boyfriend, whom she brings to Monica's Halloween party in "The One with the Halloween Party" (airdate November 1, 2001; season 8, No. 6). Phoebe is attracted to him but learns that Ursula has lied about herself in order to marry him, and so promptly warns him about Ursula's lies. He dumps her and in "The One with the Stain" and tries to get together with Phoebe, but cannot stand to look at her as she reminds him of her sister. Phoebe is able to convince him to see past that, and after she leaves for a massage client after their make-out session, she comes back only to find that Eric had sex with Ursula thinking she was Phoebe. They awkwardly decide that it is too weird to pursue things any further. Penn got the role after he made several visits to the Friends set with his children, who were fans of the show. Will Colbert Will Colbert (Brad Pitt): formerly overweight high school friend of Monica and Ross with a grudge against Rachel. Monica invites him over for Thanksgiving dinner in "The One with the Rumor" (airdate November 22, 2001; season 8, No. 9). Will has lost 150 pounds and now looks great—which makes Phoebe flirt with him. Here they find out that Will hates Rachel due to all the bullying he had suffered at her hands in high school and had co-founded the "I Hate Rachel Green Club" with Ross and spread rumors about her being a hermaphrodite. He is last seen looking bemused but amused when Joey enters the room wearing Phoebe's maternity pants (under the deluded belief that he would need to change into a new pair of pants to achieve his goal of eating an entire turkey all by himself). Pitt was married to Jennifer Aniston in real life at the time, and his given name is in fact "William". Jim Nelson Jim Nelson (James LeGros): a bully who asks Phoebe out on a date, then to amuse himself intimidates her with a number of creepy, vulgar